Why a re-index after add-on license update?

[Matt Rice]

I received a pop-up that indexing was required because of a add-on change. The only changes were update to licensing on:

Updated license key for Checklist (com.okapya.jira.checklist)
Updated license key for Essential Custom Fields for JIRA (com.primefieldsoftware.jira.essentialcustomfields)
Updated license key for Adaptavist ScriptRunner for JIRA (com.onresolve.jira.groovy.groovyrunner)
Updated license key for JIRA Misc Workflow Extensions (com.innovalog.jmwe.jira-misc-workflow-extensions)
Updated license key for Tempo Timesheets (is.origo.jira.tempo-plugin)
Updated license key for Announcer for JIRA (com.wittified.atl-announcer-jira)

However when I check the Instance Health it it reports the DB and the indexes are ok. Is this a bug or is a re-index required for license updates?

[Tibor Hegyi _META-INF_]

With potentially invalid/expired license keys used, the addons may not fully work as part of their license checking policy.

As addons sometime provide custom fields with searchers or JQL functions or other components affecting indexing, it may be necessary to reindex once the license key has been updated. This will then allow addons to resume their full functionality and to work as they are supposed to.